High and ultra-high field (3-9.4 Tesla) magnetic resonance imaging and spectroscopy (MRI/MRS) has been proven to be fundamentally advantageous due to their intrinsically high sensitivity. Recently, with the advent of new reconstruction algorithms such as SENSE and SMASH, parallel imaging, a fast imaging technique introduced some 20 years ago has been revived and has become practical and robust. This technique can dramatically reduce the minimum data acquisition time without sacrificing sensitivity. A technique combining parallel imaging with high-field MR is desired and will be ideal because it possesses both the advantages of fast acquisition time and high sensitivity. However, due to high operating frequencies at high fields, both parallel imaging and high-field MR confront RF coil design challenges such as increased radiation losses, difficult to achieve coil decoupling, increased coil/subject interactions, and complicated design and operation. These challenges have become a major obstacle for further development of parallel imaging at high fields. Therefore, we propose a comprehensive project in this application based on our newly developed microstrip transmission line (MTL) coil design concept. The major goals will be focused on (i) development of a wide variety of efficient high-frequency RF coil arrays for in-vivo high-field parallel imaging using the MTL concept; and (ii) the establishment of a simulation, modeling a wide variety of parallel MTL coil arrays for the analysis of resonant frequencies, decoupling and B1 and E fields, numerically. The proposed coil arrays are characterized by unmatched advantages of (i) a completely distributed circuit design, (ii) a high Q factor and better sensitivity, (iii) unique and efficient decoupling mechanisms, and (iv) simple and compact coil design, with easy fabrication and low cost. Successful outcomes from this research will provide a robust solution to RF coil array designs for parallel imaging at high fields and result in significant technological advances in high-field RF coil array engineering. They will be important to the future success of in vivo high-field parallel MRI/MRS.